There are many patents showing hose couplings for terminating a hose of the type used for air brake pressure lines, gasoline lines, water hoses, etc. However, in most cases those hose couplings which would be the most satisfactory are relatively expensive to manufacture. Therefore a less expensive type of hose coupling is often used which is not entirely satisfactory, since it may not adequately secure the hose to the nipple and/or screw fitting of the coupling.
Efforts to overcome prior art disadvantages have often resulted in a complex and expensive coupling using a large number of parts which require complicated machining, and which can only be assembled using special tools. Moreover, most couplings provide no interengagement between the ferrule and the screw threaded fitting, whereby all of the strain tending to pull the hose out of the coupling must be borne by the barbs on the nipple. The applicant is not aware of any prior art showing the combination on a nipple including annular barbs to provide fluid tight sealing, a threaded portion to make it easier to screw the nipple into the bore of a hose, and wrench flats inside the central opening of the nipple to receive a tool by which the nipple can be rotated during insertion thereof into the bore of the hose.